Answer:
b
Step-by-step explanation:
Looks like a badly encoded/decoded symbol. It's supposed to be a minus sign, so you're asked to find the expectation of 2<em>X </em>² - <em>Y</em>.
If you don't know how <em>X</em> or <em>Y</em> are distributed, but you know E[<em>X</em> ²] and E[<em>Y</em>], then it's as simple as distributing the expectation over the sum:
E[2<em>X </em>² - <em>Y</em>] = 2 E[<em>X </em>²] - E[<em>Y</em>]
Or, if you're given the expectation and variance of <em>X</em>, you have
Var[<em>X</em>] = E[<em>X</em> ²] - E[<em>X</em>]²
→ E[2<em>X </em>² - <em>Y</em>] = 2 (Var[<em>X</em>] + E[<em>X</em>]²) - E[<em>Y</em>]
Otherwise, you may be given the density function, or joint density, in which case you can determine the expectations by computing an integral or sum.
Answer:
shown below
Step-by-step explanation:
Look at the white squares, count them. 1, 2, 3. the next will be 4 and 5. draw 4 white squares, then house it in black squares like the others. to know if u did it right, count the black squares, there should be 8, then 9.
Answer: Yes, it is a real number. 3.4 is a rational number and rational numbers are real numbers. So 3.4 is a real number.
23. J
7,220 kids drink zero.
14,060 kids drink one
5,700 kids drink two
(multiply the total amount of kids by the percent (convert percent to decimal))
When added together, you get 26,980.
24. C
5,700 kids drink two
2,660 kids drink three
1,140 kids drink four
7,220 kids drink five or more
When added together, you get 16,720 kids.
Next set up a proportion.
38,000 total 30 total kids
------------------ = --------------------
16,720 kids x
For 38,000 to get to 30, you have to divide 38,000 by 1,266.67.
This means that you also have to divide 16,720 by 1,266.67.
This gets you 13.